Structural Biochemistry/Tumor suppressor genes

Tumors, which are neoplasms, are solid or liquid filled lesions that may or may not be formed and grown in size due to neoplastic cells. The tumor cells are part of a tissue that continually grows abnormally. It can be malignant or benign, but these cells may look like "swellings" and grow to bigger proportions. Although tumor cells that are malignant maybe confused with cancer cells, they do not invade neighboring tissues. These cells can grow and become pestering problems that affect mobility, breathing, and circulatory of bodily functions. They cells are triggered in growing by the mutations in DNA, and may have a higher chance of growing with age. (ISCID 2011)

Tumor suppressor proteins protect cells from being cancerous. Tumor suppressors play a crucial rule in not allowing the cell to divide and multiply if there is damage to the cell’s DNA; this will occur until the DNA of the cell is repaired. In the event DNA cannot be repaired, tumor suppressors play a role in the process called “apoptosis”, which is the process of programmed cell death. If tumor suppressors do not function properly in a cell with damaged DNA, the cell continue dividing and replicating damaged DNA, which eventually leads to cancer.

Examples of tumor suppressor proteins:

 * p53 is a protein that is responsible for preventing cell division of cells that have damaged DNA
 * p63 is part of the p53 family and has a similar structure to bother p53 and p73. However, the function of p63 seems to be more similar to p73 than p53.
 * p73 is a protein that is part of the p53 family and is structurally and functionally similar to p53
 * PTEN stands for phosphatase and tensin homologprotein and is involved in the pathway that signals for a cell to stop dividing and triggers apoptosis
 * Retinoblastoma is a protein that is responsible for repressing the transcription of genes regulated by E2F, which include cyclins that regulate the cell cycle.
 * APC Adenomatous polyposis coli (APC) or also known as deleted in polyposis 2.3 (DP2.5) is a protein found in humans that are coded by the APC gene.